Mage slayer gives disadvantage on concetration on all attacks or just on the reactive one?

Mage Slayer:

When a creature within 5 ft. of you casts a spell, you can use your reaction to make a melee weapon attack against that creature, and when you damage a creature that is concentrating on a spell, that creature has disadvantage on the saving throw it makes to maintain its concentration. You also have advantage on saving throws against spells cast by creatures within 5 ft. of you.

Does that mean that when this PJ hits a mage concentrating on a spell with the Attack action on their turn, they also have disadvantage? Or does it just happen when the attack occurs upon being triggered by a spell being cast on mele range?

Does the Mind Flayers Innate Spellcasting (Psionics) trigger the melee weapon attack granted by the Mage Slayer feat?

While searching for an answer i found this and this question about counterspelling a Mind Flayer. Which does not work because Counterspell states in it’s reaction trigger:

when you see a creature within 60 feet casting a spell

and the Mind Flayers Innate Spellcasting tells us:

It can cast the following spells, requiring no components

So we know, Counterspell does not work because a Mind Flayers spellcasting is not observable.

However Mage Slayer reads like this:

When a creature within 5 feet of you casts a spell, you can use your reaction to make a melee weapon attack against that creature.

RAW this seems to mean, that a Mind Flayer triggers that melee weapon attack because Mage Slayer does not require you to see the spellcasting. This feels wrong to me because there is no way to even tell the mind flayer casted a spell except the spells effect which might be observable (levitate) or not (detect thoughts).

Is there some kind of ruling, that i am missing?

How to make Mage: the Awakening feel more superheroic

I have just started GMing a Mage: the Awakening game, and I can already tell what my players like and dislike about the game. They like using their (limited) magical powers to the fullest extent, they like tangling with supernatural creatures and spirits, they like subtle political machinations, and they like screwing with Sleepers. What they don’t like is Paradox, Atlantean history, Wisdom degeneration, and weird gnostic metaphors.

How do I make Mage feel more like a gritty, dark, superheroic game and less like a grimdark exploration of the human soul? My players don’t want to live in a world of moral absolutes, or have easily identified villains. In fact, they are just as likely to be the villains.

Can Mage Hand be used to use a Ballista?

In the DMG page 255-256 are several siege weapons described which are actually objects. It takes actions to load, aim and fire the siege weapons. For the ballista for example it says:

It takes one action to load the weapon, one action to aim it, and one action to fire it.

I have always imagined you have to stand in 5 feet of the object and then take the "load", "aim" or "fire" action. In the decription for Mage Hand it says:

You can use your action to control the hand. You can use the hand to manipulate an object, open an unlocked door or container, stow or retrieve an item from an open container, or pour the contents out of a vial.

So technically the mage hand can manipulate an object but can it "load", "aim" or "fire" a ballista?

Can Mage Hand pour out a vial of acid?

The description of Mage Hand says:

You can use your action to control the hand. You can use the hand to manipulate an object, open an unlocked door or container, stow or retrieve an item from an open container, or pour the contents out of a vial (PHB p.246)

while the description of Acid (vial) says:

As an action, you can splash the contents of this vial onto a creature within 5 feet of you or throw the vial up to 20 feet, shattering it on impact. In either case, make a ranged attack against a creature or object, treating the acid as an improvised weapon. (PHB p. 148, “Adventuring Gear”)

However Mage Hand also states:

The hand can’t attack, activate magic items, or carry more than 10 pounds.

So the question is can Mage Hand pour out Acid (vial) onto an enemy? And if it can be poured, would the damage require an attack roll from the caster or a dex saving throw from the target? If it is an attack roll, then what does it scale off of and how would proficiency be determined? If it is a saving throw, then how is the DC calculated (either a specific DC to the vial/Mage Hand or the caster’s spell save DC)?

Is a concentration check required for each of my following spells if I buff myself with Mage Armor

Player’s Handbook 1, p. 170, "Concentration" – "Spell" says:

"If you are affected by a spell while attempting to cast a spell of your own, you must make a Concentration check or lose the spell you are casting."

Now I have the feeling I played DnD wrong for years – this means if I buff myself with e.g. "Mage Armor" and try to cast "Magic Missiles" the next round, I have to do a concentration check, correct? And someone I buff with another spell, too?

There is no mentioning of the spell affecting me being from someone else or hostile.

What can remove the bane effects of Elder Runes in Dungeon of the Mad Mage?

In the campaign Dungeon of the Mad Mage there are bane effects on Elder Runes that are cast like symbol. One of the runes mentions specifically that it can be dispelled by remove curse or greater restoration and the others with lingering affects say nothing. Am I to infer that these other effects cannot be dispelled and just have to wear off over time?

Can Mage Hand drag more weight than it can carry?

I have been watching/listening to Chance’s D&D Spellbook, which highlights a potential ‘loophole’ in that the spell doesn’t list how much the hang can drag, say if attached via a rope that weighs less than 10lbs.

Normally a spell only does what it says, but carrying and dragging seem closely enough related that there might be some room for interpretation.